fix: mypy/typing CI for v3.0.3

Author: erik-sv

docs/package/changelog.md

@@ -9,6 +9,10 @@ This document provides a chronological list of notable changes for each version
   - `ENCYPHER_C2PA_CONTEXT_URL` controls the emitted `@context` during embedding.
   - `ENCYPHER_C2PA_ACCEPTED_CONTEXTS` controls the verifier allowlist (JSON list or comma-separated string).
 - Default verifier allowlist accepts both C2PA schema contexts v2.2 and v2.3 to avoid false `SIGNATURE_INVALID` failures when signing emits v2.3.
+- Restored green CI by fixing `mypy` typing issues:
+  - Corrected internal helper type signatures.
+  - Added missing return type annotations.
+  - Cleaned up unused imports caught by linters.
 
 ## 3.0.2 (2026-01-10)
 

encypher/core/__init__.py

@@ -2,6 +2,8 @@
 Core encoding and decoding functionality for Encypher.
 """
 
+from typing import Any
+
 from encypher.core.keys import generate_ed25519_key_pair as generate_key_pair
 from encypher.core.keys import load_private_key_from_data as load_private_key
 from encypher.core.keys import load_public_key_from_data as load_public_key
@@ -21,7 +23,7 @@
 ]
 
 
-def __getattr__(name: str):
+def __getattr__(name: str) -> Any:
     if name in {"MetadataTarget", "UnicodeMetadata"}:
         from encypher.core.unicode_metadata import MetadataTarget, UnicodeMetadata
 

encypher/core/unicode_metadata.py

@@ -20,7 +20,6 @@
 from cryptography.exceptions import InvalidSignature
 from cryptography.hazmat.primitives.asymmetric import ed25519
 from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey, Ed25519PublicKey
-from cryptography.hazmat.primitives.asymmetric.types import PrivateKeyTypes
 
 from encypher import __version__
 from encypher.config.settings import Settings
@@ -737,7 +736,7 @@ def embed_metadata(
             return embedded_text
 
     @staticmethod
-    def _compute_text_hash(cls, text: str, algorithm: str = "sha256") -> str:
+    def _compute_text_hash(text: str, algorithm: str = "sha256") -> str:
         """Compute hex digest of *text* using *algorithm* after NFC normalization."""
         import hashlib
         import unicodedata
@@ -754,7 +753,7 @@ def _compute_text_hash(cls, text: str, algorithm: str = "sha256") -> str:
     def _embed_c2pa(
         cls,
         text: str,
-        private_key: PrivateKeyTypes,
+        private_key: SigningKey,
         signer_id: str,
         claim_generator: Optional[str],
         actions: Optional[list[dict[str, Any]]],